package org.pzy.java.base;

/**
 * @Author: DRevelation
 * @Date: 2022/4/14 17:33
 */
public class MathDemo {
    public static void main(String[] args) {
        double v = Math.log(12);
        System.out.println(v);

        String ss = "abcdddddddddddddddddddddddddddd";
        if (ss.length() > 20) {
            String popTitle = ss.substring(0, 20);
            System.out.println(popTitle);
        } else {
            System.out.println("error");
        }
    }
}
